Download Domain - Eukarya

Domain – Eukarya
Kingdom - Protista
Features of this Protista
Kingdom
• Eukaryotic Cell (has true nucleus and
organelles)
• Most are Unicellular
(some are multicellular)
• Examples: trypanosome, amoeba
Classification
Kingdom:
Phylum:
Class:
Order:
Family
Genus:
Species:
Protista
Euglenozoa
Euglenoidea
Kinetoplastea
Trypanosomatidae
Trypanosoma
brucei
Subspecies
T. b. gambiense
T. b. rhodesiense
T. b. brucei
Organism Structure
Inside the Cell
Trypanosomes under microscope
• http://www.youtube.com/watch?v=EnsydwITL
Yk&feature=related
Monsters Inside Us
• http://www.youtube.com/watch?v=4aVUrGO
97Zg
Areas Affected by Disease
Life Cycle
• http://www.genomics.liv.ac.uk/tryps/trypsmo
vie.html
Bloodstream and Procyclic Forms
Method of Transmission
Tsetse fly
Genus:
Glossina
E.g. Glossina fusca
(forest species)
http://www.youtube.com/watch?v=Q_nCHDry0s8
Tsetse fly
• http://www.youtube.com/watch?v=Q_nCHDr
y0s8
Bloodstream Form – Antigenic
Variation
Antigenic Variation
Antigenic Variation
• When a trypanosome enters the bloodstream of a host
(e.g. human) the white blood cells of the host try to
attack the trypanosomes by producing antibodies which
would help to kill the parasite.
• This is because the trypanosome cell contains proteins in
its cell membrane which the white blood cells recognise
as ‘foreign’ (i.e. not belonging to the host).
• These proteins in the trypanosome, that the white blood
cells respond to, are called antigens.
• The white blood cells make antibodies which are a
specific to these antigens. An antibody will only bind to a
specific antigen.
• Many trypanosomes are killed off by the white
blood cells and their antibodies. However by the
time the white blood cells have produced the
antibody, some trypanosomes have started to
change their protein coat.
• They do this by ‘switching on’ different genes in
their DNA. They have now made new proteins
(i.e. new antigens). The antibody cannot bind to
this new antigen and so it is useless.
• The white blood cells respond by making new
antibodies for this new antigen. However by
the time the new antibody is made, some
trypanosomes have changed their protein
coat once again.
• This process continues and the protein coat
keeps changing, so that the organism can
continue to survive, despite being constantly
attacked by the immune system.
• This process is called antigenic variation.
African Sleeping Sickness
• http://www.youtube.com/watch?v=Dym13KU
gD14
• http://www.youtube.com/results?search_que
ry=symptoms+african+sleeping+sickness&aq=f
Symptoms African Sleeping Sickness
First Stage:
• Fever
• Headaches
• joint pains
• Itching
• Swelling of lymph nodes
Second Stage: when parasite invades
central nervous system and crosses into
brain
• confusion
• reduced coordination,
• disruption of the sleep cycle, with bouts
of fatigue and periods of mania
• without treatment can lead to death